// Copyright 2011 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_PROFILER_CIRCULAR_QUEUE_INL_H_
#define V8_PROFILER_CIRCULAR_QUEUE_INL_H_

#include "src/profiler/circular-queue.h"

namespace v8 {
namespace internal {

    template <typename T, unsigned L>
    SamplingCircularQueue<T, L>::SamplingCircularQueue()
        : enqueue_pos_(buffer_)
        , dequeue_pos_(buffer_)
    {
    }

    template <typename T, unsigned L>
    SamplingCircularQueue<T, L>::~SamplingCircularQueue() = default;

    template <typename T, unsigned L>
    T* SamplingCircularQueue<T, L>::Peek()
    {
        base::SeqCst_MemoryFence();
        if (base::Acquire_Load(&dequeue_pos_->marker) == kFull) {
            return &dequeue_pos_->record;
        }
        return nullptr;
    }

    template <typename T, unsigned L>
    void SamplingCircularQueue<T, L>::Remove()
    {
        base::Release_Store(&dequeue_pos_->marker, kEmpty);
        dequeue_pos_ = Next(dequeue_pos_);
    }

    template <typename T, unsigned L>
    T* SamplingCircularQueue<T, L>::StartEnqueue()
    {
        base::SeqCst_MemoryFence();
        if (base::Acquire_Load(&enqueue_pos_->marker) == kEmpty) {
            return &enqueue_pos_->record;
        }
        return nullptr;
    }

    template <typename T, unsigned L>
    void SamplingCircularQueue<T, L>::FinishEnqueue()
    {
        base::Release_Store(&enqueue_pos_->marker, kFull);
        enqueue_pos_ = Next(enqueue_pos_);
    }

    template <typename T, unsigned L>
    typename SamplingCircularQueue<T, L>::Entry* SamplingCircularQueue<T, L>::Next(
        Entry* entry)
    {
        Entry* next = entry + 1;
        if (next == &buffer_[L])
            return buffer_;
        return next;
    }

} // namespace internal
} // namespace v8

#endif // V8_PROFILER_CIRCULAR_QUEUE_INL_H_
